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Overview of Numeric Nutrient Criteria Development and Implementation in Montana

Overview of Numeric Nutrient Criteria Development and Implementation in Montana. Michael Suplee, PhD Water Quality Standards Section Montana Department of Environmental Quality Presented to the Water Pollution Control Advisory Council February 17, 2012. Presentation Outline.

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Overview of Numeric Nutrient Criteria Development and Implementation in Montana

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  1. Overview of Numeric Nutrient Criteria Development and Implementation in Montana Michael Suplee, PhD Water Quality Standards Section Montana Department of Environmental Quality Presented to the Water Pollution Control Advisory Council February 17, 2012

  2. Presentation Outline • Brief timeline of criteria development in Montana • Why numeric nutrient criteria? • Criteria derivation: methods overview • Wadeable streams, Large rivers, Lakes/reservoirs • Trends on the Clark Fork River • Implementation: Meeting the standards over time • Senate bills 95 and 367 • Nutrient Work Group • Draft Circular DEQ-12 and new rules • USEPA acceptance of Montana’s approach • Timeline: adoption of statewide nutrient criteria

  3. Brief and Incomplete Overview of Nutrient Criteria Development in Montana • 1990s: Clark Fork River criteria derived; VNRP • 2001: DEQ begins criteria development for all waters • 2002: Clark Fork River criteria adopted as standards • 2003-2008: Statewide criteria for wadeable streams generally identified, and a system for establishing different criteria zones developed by DEQ • 2009: SB 95 adopted, allows variances from nutrient standards on a case-by-case. NWG created • 2011: SB 367 adopted, refining variance process, allows for general variances

  4. Why Numeric Nutrient Criteria? • Existing standards are narrative (“no nuisance aquatic life”, etc.) • Intent fairly clear, application inconsistent • Nutrient (i.e., nitrogen and phosphorus) over-enrichment directly and indirectly impacts other, existing numeric WQ standards: • Dissolved oxygen, pH, nuisance algal growth, etc. Better to address root cause via nutrient standards • Allows for more consistent permitting and TMDL application

  5. Clark Fork River Nuisance algal growth, rivers & streams

  6. Actual/likely affects on stream uses at varying algae levels (wadeable streams) Recreation acceptable Recreation unacceptable Increasing salmonid growth & survival Salmonid growth & Survival high ? Salmonid growth & survival very likely impaired Salmonid growth & Survival possibly reduced No DO problems Possible DO problems DO problems very likely Stonefly, mayfly caddis- fly dominant Shift in biomass & community structure Midges, worms, mollusks, scuds dominant 0 50 100 150 200 250 300 350 400 450 500 Benthic algae level (mg Chla/m2)

  7. Nutrient Criteria Derivation: Wadeable Streams 3 major parts: • Identification of appropriate geographic zones in which specific nutrient criteria (total P, total N) would apply • Understanding of cause-effect (i.e., stressor-response) relationships between nutrients and beneficial uses • Requires determining “harm to use” • Different expectations for different regions of the state • Water quality data from reference sites • Data from 2 and 3 above can (and should) be considered together

  8. Montana Ecoregions (level III, IV) Mountainous Prairie

  9. Dose-response studies carried out in a level III ecoregionoccurring in MT (except Mebane [2010])

  10. Reference Stream Sites Nutrient concentration data from reference streams — which support all their beneficial uses and have minimal impacts — are compiled for each ecoregion (III, and IV if possible) Western MT reference stream site Eastern MT prairie-stream reference site

  11. Comparing reference data and dose-response study results 50th percentile (median) Range of nutrient concentrations across which impacts to beneficial stream uses are likely to begin to occur 25th 75th percentile Frequency 99th percentile Regional Reference-stream Nutrient Concentrations

  12. Coming Soon: Ecoregion-by-ecoregion discussion of how criteria were established(addendum to Suplee et al. 2008)

  13. Nutrient Criteria Derivation: Large Rivers • No comparable reference available, as for wadeables • Large rivers much deeper/faster than wadeablestreams; changes light regime and other factors Solution: Use mechanistic water-quality models • Can vary nutrient inputs in model and observe effects on other water quality parameters/standards, like • DO • Nuisance benthic algae growth • pH • Total organic carbon (TOC) • Total dissolved gas (TDG)

  14. Lower Yellowstone River • Used QUAL2K model to derive criteria • Steady state • Simulates benthic algae • Study reach 232.9 km or 145 miles • Low flows near 100 m3/sec (3,280 cfs) ; free flowing

  15. For wadeable streams/large rivers, criteria apply seasonally (summer and fall) only, when algal growth is peak and ensuing water quality impacts are maximal

  16. Nutrient impacts to lakes • Loss of water clarity; reduction of recreation and aesthetic quality and property value • Increased frequency of noxious algae blooms • Changes in fish species composition • Loss of macrophytes, replaced by dense phytoplankton • Taste and odor problems (drinking water source)

  17. Nutrient Criteria Derivation: Lakes and Reservoirs • Under development. Data collection in Montana lakes was completed between 2003-2008 • Reservoirs pending. Plan to use a modeling approach • Canyon Ferry Reservoir first project; 2013-14 • No lake or reservoir criteria will be recommended for rule making this year except perhaps Flathead Lake

  18. How Goes the Clark Fork River? • 1998: Stakeholders develop voluntary nutrient reduction plan (VNRP) and implementation process. • Basin-wide phosphorus ban in place since 1989 • Criteria adopted as rules by state in 2002 • 2004: Major nutrient reduction efforts in place (e.g., BNR plant in Missoula) Site 18, Clark Fork River below Missoula, 1998-2009

  19. Implementation: Statewide approach to meet the standards over time

  20. Implementation: Economic Considerations • Option are available for communities to receive temporary relief from the requirements based on: • Ability to pay for treatment (affordability) • Availability of treatment technology (limits of technology) • These options apply only to wastewater treatment beyond the federally mandated technology-based regulations (i.e., National Secondary Standards)

  21. Senate bills 95 (2009 Legislature) and 367 (2011 Legislature) (now §75-5-313, MCA) • Give DEQ authority to grant variances from nutrient criteria, based on substantial & widespread economic harm that would result from immediate implementation of the standards • Variances up to 20 years, subject to 3-year reviews • General Variance: If permittee can’t meet criteria, but can treat effluent to statute-defined levels, they will receive a gen. variance, by groups: • > 1 MGD: 1 mg TP/L, 10 mg TN/L • < 1 MGD: 2 mg TP/L, 15 mg TP/L • Lagoons: Maintain current performance (implies monitoring requirements) • Individual Variance: Permittee may apply for these if meeting the general variance is difficult. Requires case-by-case economic hardship analysis

  22. OVERALL: Law allows Montana to implement numeric nutrient criteria in a staged manner over ~ 20 years, allowing critical time to better address all sources of nutrient pollution (point and nonpoint) and for treatment technology to improve/come down in cost

  23. §75-5-313, MCA • Describes the “Nutrient Work Group” • Broad cross-section of MT stakeholders • Advise DEQ on numeric nutrient standards, especially implementation policy • Have met with DEQ 15 times since May 2009 • Nutrient trading policy developed • Will allow for creation of nutrient credits and trading between point sources and point source-nonpoint sources

  24. Draft Circular DEQ-12 and New Rules Contain: • Criteria • General variance procedures • Individual variances • Permitting requirements • Non-degradation http://deq.mt.gov/wqinfo/NutrientWorkGroup/default.mcpx

  25. New! EPA acceptance of Montana’s approach In an official memo (1/3/2012) USEPA states: • “We recognize the strong science-based work MDEQ has conducted over the past several years to develop draft NNC for N and P for wadeable streams” • “EPA concludes that the issuance of variances would be consistent with the Clean Water Act and its implementing regulations.”

  26. Timeline: Adoption of Statewide Nutrient Criteria • Next NWG Meeting: 2/27/2012 (Helena, MT) • More NWG meetings to follow (~ monthly) Assuming details get worked out: • Board package in July or September, 2012 • Public hearings, response to comments, modifications, etc. • So…Need to get rule package to WPCAC this Spring

  27. Thank You Contact Information: • (406) 444-0831 • msuplee@mt.gov

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